TY - JOUR
T1 - Pressure-induced rotational symmetry breaking in URu2Si2
AU - Choi, J.
AU - Ivashko, O.
AU - Dennler, N.
AU - Aoki, D.
AU - Von Arx, K.
AU - Gerber, S.
AU - Gutowski, O.
AU - Fischer, M. H.
AU - Strempfer, J.
AU - Zimmermann, M. V.
AU - Chang, J.
N1 - Funding Information:
The authors are grateful to P. W. J. Moll, S. Benhabib, M. Janoschek, R. Flint, and H. Nojiri for inspiring discussions. J.C., O.I., and J.C. thank the Swiss National Science Foundation for support through Grant No. BSSGI0_155873. D.A. acknowledges support from the MEXT of Japan Grant-in-Aid for Scientific Research (through Grants No. JP15H05882, No. JP15H05884, No. JP15K21732, No. JP15H05745, and No. JP16H04006) and the European Research Council (through ERC-starting grant - NewHeavyFermion).
Publisher Copyright:
© 2018 American Physical Society.
PY - 2018/12/27
Y1 - 2018/12/27
N2 - Phase transitions and symmetry are intimately linked. Melting of ice, for example, restores translation invariance. The mysterious hidden order (HO) phase of URu2Si2 has, despite relentless research efforts, kept its symmetry breaking element intangible. Here, we present a high-resolution x-ray diffraction study of the URu2Si2 crystal structure as a function of hydrostatic pressure. Below a critical pressure threshold pc≈3 kbar, no tetragonal lattice symmetry breaking is observed even below the HO transition THO=17.5 K. For p>pc, however, a pressure-induced rotational symmetry breaking is identified with an onset temperatures TOR∼100 K. The emergence of an orthorhombic phase is found and discussed in terms of an electronic nematic order that appears unrelated to the HO, but with possible relevance for the pressure-induced antiferromagnetic (AF) phase. Existing theories describe the HO and AF phases through an adiabatic continuity of a complex order parameter. Since none of these theories predicts a pressure-induced nematic order, our finding adds an additional symmetry breaking element to this long-standing problem.
AB - Phase transitions and symmetry are intimately linked. Melting of ice, for example, restores translation invariance. The mysterious hidden order (HO) phase of URu2Si2 has, despite relentless research efforts, kept its symmetry breaking element intangible. Here, we present a high-resolution x-ray diffraction study of the URu2Si2 crystal structure as a function of hydrostatic pressure. Below a critical pressure threshold pc≈3 kbar, no tetragonal lattice symmetry breaking is observed even below the HO transition THO=17.5 K. For p>pc, however, a pressure-induced rotational symmetry breaking is identified with an onset temperatures TOR∼100 K. The emergence of an orthorhombic phase is found and discussed in terms of an electronic nematic order that appears unrelated to the HO, but with possible relevance for the pressure-induced antiferromagnetic (AF) phase. Existing theories describe the HO and AF phases through an adiabatic continuity of a complex order parameter. Since none of these theories predicts a pressure-induced nematic order, our finding adds an additional symmetry breaking element to this long-standing problem.
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U2 - 10.1103/PhysRevB.98.241113
DO - 10.1103/PhysRevB.98.241113
M3 - Article
AN - SCOPUS:85059537069
SN - 2469-9950
VL - 98
JO - Physical Review B
JF - Physical Review B
IS - 24
M1 - 241113
ER -